Herpes zoster is a painful, cutaneous eruption of vesicular lesions that usually occurs in a dermatomal distribution, caused by reactivation of varicella zoster virus (VZV). Reactivation of VZV as herpes zoster is a well-recognized cause of morbidity in the HIV-infected host. It has been described as both an early and a late manifestation of HIV infection. The objective of this study is to evaluate whether the immune response to VZV can be safely boosted in HIV-infected subjects with a prior history of chickenpox using the live-attenuated varicella vaccine. Although in general, live attenuated vaccines are avoided in subjects with HIV, the proposed use of varicella vaccine should be safe for several reasons: 1) It has been found to be safe in immunocompromised children and adolescents. 2) Preliminary data from a Pediatric AIDS Clinical Trials Group study has shown the vaccine to be safe in HIV-infected children who had not had prior infection with varicella zoster. There were no serious adverse clinical events and no detectable alteration in the HIV infection in this study. VZV specific T cell mediated immunity was stimulated in 80% of vaccines by two doses of vaccine. 3) We propose administering the vaccine to adults known to have had varicella infection in the past, who therefore possess some specific immunity to the varicella zoster virus. 4) Recipients will be watched closely for evidence of clinical infection, and will have effective antiviral treatment available to abort serious disease secondary to varicella. Primary objectives a) To determine the safety of live-attenuated varicella zoster vaccine in HIV-infected adult patients at weeks 12 and 24. b) To monitor the immune responses to vaccination with live-attenuated varicella zoster vaccine in HIV-infected adult patients through VZV antibody and in-vitro responder cell frequency (RCF). Secondary objectives: a) To determine the durability of immune responses to vaccination with live-attenuated varicella zoster vaccine in HIV-infected adult patients. b) To monitor the frequency and nature of VZV infections following immunization with live-attenuated varicella vaccine. c) To examine the gamma-interferon (IFN), IL2, and CTL production of VZV-stimulated PBMC cultures in HIV-infected adults who receive live-attenuated varicella vaccine. d) To compare levels of varicella antibody and varicella specific cell-mediated immune responses in HIV-infected patients with age and sex matched HIV-negative controls at baseline and in response to vaccination with live-attenuated varicella vaccine.